Subject: Re: bug#12745: crash in bidi_pop_it during (idle) redisplay

From: Eli Zaretskii <[email-masked]>
Date: Sun, 28 Oct 2012 19:23:38 +0200

> Date: Sun, 28 Oct 2012 00:50:08 -0700
> From: Paul Eggert <[email-masked]>
> 
> > First, please file a bug about this via "M-x report-emacs-bug RET".
> >
> 
> When? :)
> (after the crash, the process is gone, so can't M-x anything; before the
> crash, there's nothing interesting to report :))

That's not true, the important information is about your system,
environment, and packages loaded into Emacs, so a report from the same
kind of session will do.

> In case it's interesting, appended the info from r-e-b (from an emacs -Q
> instance) to the bottom of this email.

Thanks.  But I'd like to see the report from your normal session,
invoked just as you invoke those that crash.

> (gdb) p it->current
> $3 = {
>   pos = {
>     charpos = 1295,
>     bytepos = 1295
>   },
>   overlay_string_index = 0,
>   string_pos = {
>     charpos = -1,
>     bytepos = -1
>   },
>   dpvec_index = -1
> }

So this seems to say that there's at least one overlay string at
buffer position 1295.  Is that reasonable?  What was the current
buffer when this crashed?  You can find that out by typing this at GDB
prompt:

  (gdb) pp current_buffer->name_

(If "pp" doesn't work, type "source /path/to/emacs/src/.gdbinit" and
try again.)

You can display the relevant part of the text of that buffer like
this:

  (gdb) p current_buffer->text->beg[1200]@100

What does this show?

Also, what do the following commands produce?

  (gdb) frame 6
  (gdb) pgrowx it->glyph_row

> > Third, could you please try the latest development code, and possibly
> > compile without optimizations?
> 
> 
> Will do & report back in a few days (or sooner, if the bug recurs in HEAD).

Thanks, but please also show the above information for the version
that did crash.